SCHEDULE 13G

CUSIP No.

1

Names of Reporting Persons

ADVENT INTERNATIONAL, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

11

Percent of class represented by amount in row (9)

0.00 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No.

1

Names of Reporting Persons

Advent International GP, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

11

Percent of class represented by amount in row (9)

0.00 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP No.

1

Names of Reporting Persons

Advent-NCS Acquisition Limited Partnership

2

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

11

Percent of class represented by amount in row (9)

0.00 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

NCS Multistage Holdings, Inc.

(b)

Address of issuer's principal executive offices:

19350 State Highway 249, Suite 600, Houston, Texas 77070

Item 2.

(a)

Name of person filing:

This Statement is being jointly filed by each of the persons below on behalf of various funds and accounts (which may have been included on prior Statements filed with respect to the Issuer) controlled or managed by such persons, whom together are referred to herein as the "Reporting Persons": (i) Advent International, L.P.; (ii) Advent International GP, LLC; and (iii) Advent-NCS Acquisition Limited Partnership.

(b)

Address or principal business office or, if none, residence:

Prudential Tower, 800 Boylston Street, Boston, Massachusetts 02199

(c)

Citizenship:

See response to row 4 on each cover page hereto.

(d)

Title of class of securities:

Common Stock, par value $0.01 per share

(e)

CUSIP No.:

Item 4.

Ownership

(a)

Amount beneficially owned:

See response to row 9 on each cover page hereto.

(b)

Percent of class:

See response to row 11 on each cover page hereto.

(c)

Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

See response to row 5 on each cover page hereto.

(ii) Shared power to vote or to direct the vote:

See response to row 6 on each cover page hereto.

(iii) Sole power to dispose or to direct the disposition of:

See response to row 7 on each cover page hereto.

(iv) Shared power to dispose or to direct the disposition of:

See response to row 8 on each cover page hereto.

Item 5.

Ownership of 5 Percent or Less of a Class.

Ownership of 5 percent or less of a class

Item 6.

Ownership of more than 5 Percent on Behalf of Another Person.

Not Applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not Applicable

Item 8.

Identification and Classification of Members of the Group.

Not Applicable

Item 9.

Notice of Dissolution of Group.

Not Applicable

Item 10.

Certifications:

Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

ADVENT INTERNATIONAL, L.P.

Signature:	/s/ Neil Crawford
Name/Title:	Neil Crawford / Senior Director, Fund Administration of Advent International GP, LLC, its General Partner
Date:	09/01/2026

Advent International GP, LLC

Signature:	/s/ Neil Crawford
Name/Title:	Neil Crawford / Senior Director, Fund Administration
Date:	09/01/2026

Advent-NCS Acquisition Limited Partnership

Signature:	/s/ Neil Crawford
Name/Title:	Neil Crawford / Senior Director, Fund Administration of Advent-NCS GP LLC, its General Partner
Date:	09/01/2026

Exhibit Information

99.1 Joint Filing Agreement, dated September 1, 2026